“War on Terror” First Used

The War on Terror (WoT), also known as the Global War on Terrorism (GWOT), refers to the international military campaign that started after the September 11, 2001 attacks on the United States. The United States led a coalition of other countries in a long but unsuccessful campaign to destroy al-Qaeda and other militant Islamist organizations.

U.S. President George W. Bush first used the term "War on Terror". The Bush administration and the western media have since used the term to argue a global military, political, legal, and conceptual struggle against both organizations designated terrorist and regimes accused of supporting them. It was originally used with a particular focus on Muslim countries associated with Islamic terrorism organizations including al-Qaeda and like-minded organizations.

In 2013, President Barack Obama announced that the United States was no longer pursuing a War on Terror, as the military focus should be on specific enemies rather than a tactic. He stated, "We must define our effort not as a boundless 'Global War on Terror', but rather as a series of persistent, targeted efforts to dismantle specific networks of violent extremists that threaten America."
 
U.S. President George W. Bush first used the term "War on Terror" on 20 September 2001.

http://en.wikipedia.org/wiki/War_on_Terror
http://www.findingdulcinea.com/news/on-this-day/September-October-08/On-this-Day--President-Bush-Declares--War-on-Terror-.html